
<!DOCTYPE html>
<html>

<head>
    <meta charset="UTF-8" />
    <link rel="stylesheet" href="./../../cesium/Cesium1.98/Widgets/widgets.css">
    <script type="text/javascript" src="./../../cesium/Cesium1.98/Cesium.js"></script>
    <script src="./latlng.js"></script>
    <script src="./analyser.js"></script>
    <script src="./viewshed.js"></script>
</head>

<body style="margin: 0; overflow: hidden; background: #fff; width: 100%; height: 100%; position: absolute; top: 0">
    <div id="map" style="margin: 0 auto; width: 100%; height: 100%"></div>

    <script type="text/javascript">

        Cesium.Ion.defaultAccessToken = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJqdGkiOiI3ZjQ5ZGUzNC1jNWYwLTQ1ZTMtYmNjYS05YTY4ZTVmN2I2MDkiLCJpZCI6MTE3MTM4LCJpYXQiOjE2NzY0NDUyODB9.ZaNSBIfc1sGLhQd_xqhiSsc0yr8oS0wt1hAo9gbke6M'
        const viewer = new Cesium.Viewer('map', {
            contextOptions: {
                requestWebgl1: true,
            },
        });
        // 开启帧率
        viewer.scene.debugShowFramesPerSecond = true;

        // 加载默认地形
        viewer.terrainProvider = Cesium.createWorldTerrain({
            requestWaterMask: true, // 请求水掩膜以实现水体效果
            requestVertexNormals: true // 请求法线以实现光照效果
        });

        // 深度监测
        viewer.scene.globe.depthTestAgainstTerrain = true;

        var viewsheds = [];

        var options = {
            qdOffset: 2,
            zdOffset: 2
        };
        var viewshed2 = new viewshed(viewer, options);
        viewsheds.push(viewshed2);

        function click_clear() {
            viewsheds.forEach((element) => {
                element.clear();
            });
        }


    </script>
</body>

</html>